Electrical furnace



Doc. 15, 1931. n. MoKNlGHT ELECTRIGAL FURNACE 151m oet. e. 192s s sheets-snm 1 I INVENToR. Hober/ l 1 l l o ooo \NNQN N an n ma ` D 15,1931. C R. MCKNIGHT 1.8361721 nnnc'rnxcn. runnen Filed oct'. e. 1929 A:sheets-snm s J6 Y i J5' INVENTOR. Joer'M 1 AT EY.

Patented Dec. 15, 1931 l i UNITED STATES PATENT OFFICE ROBERT MCXNIGHT, F PITTSBURGH, PENNSYLVANIA ELECTRICAL FURNACE Application led October 8, 1929. Serial No. 398,217.

This invention relates to an electrical furprovide, in a manner as hereinafter' set forth, nace for reducing ores and metallic coman apparatus for the purpose referred to pounds intometals, and has for its primary which is simple in its construction and ar object to provide, in a manner as hereinafter rangement, strong, durabie, compact, thorl set forth, to reduce the ore or metallic comoughly eiiicient in its use, readily assembled, 58 pound in a manner whereby the resultant and comparatively inexpensive to operate for metal will be free of slag. the purpose intended.

A further object of the invention is to pro- With the foregoing and other objects in vide, in a manner as hereinafter set forth for view the invention consists of the novel conthe freeing of any metal that may be reduced struction, combination and arrangement of G0 that is contained in the gangue matter or slag. parts as hereinafter more specifically de- A further object of the invention is to proscribed, and illustrated in the accompanying vide, in a manner as hereinafter set forth for drawings, wherein is shown an embodiment the discharge of the metal from the bottom of the invention, but it is to be understood l5 of a reducing chamber and with the metal that changes, variations and modifications 65 being free of slag. can be resorted to which fall within the scope- A further object of the invention is to proof the claims hereunto appended. vide, in a manner as hereinafter set forth for In the drawings wherein like reference. the removal from the material being treated characters denote corresponding parts gangue matter during the travel of the ma throughout the several views 70 terial. y, Figure l is a longitudinal sectional view of A further object of the invention is to proan electrical furnace for reducing ores and vide, in a manner as hereinafter set forth for metal compounds into metal. successively submitting, at different levels, Figure 2 is a sectional plan of an element the material to reducing temperatures during or unit of furnace providing a melting 75 the continuous travel of the material while chamber. being treated, and subsequently to eachre- Figure 3 is a sectional plan illustrating the ducing step dropping the material from a forni of reducing chamber. higher to a lower level to assist in throwing Figure 4 is a vertical sectional view illusofi' the gases and nfurther for freeing any trating the form of reducing chamber. 80 metal which might be reduced that is con- Figures 5 and 6 are respectively a sectional tained in the slag. plan and a cross section of the reducing l A further object of the invention is to prochamber showing a modified form of elecvide, in a manner as hereinafter set forth, a trode arrangement. series of reducing chambers arranged in step- The furnace may be set up with as many 83 like form at different levels to provide a drop reduction elements or units as desired the for the material when discharged from one units however progressively increase in reducing chamber into another, communicatheight from the discharge end to the intake ing means between the reducing chambers, end of the furnace. As illustrated appagas lead-off pipes for the reducing chambers ratus is shown as including a .set of six re 9i and a common discharge pipe for said gas duction units designated generaiiy at l0, il, lead-oif pipes. l2, 13,14 andl', and which provide the re- A further object of the invention is to production chambers 16, 17, i8, i5), 2G 2i revide, in a manner as hereinafter set forth, spectively. a series of spaced reducing chambers progres- As the reduction units are of the same con @5 sively arranged at different levels from front struction, but one will be described, as the to rear, and with each chamber having means description of one will applj to the other. for the discharge of slag during the travel Each reduction unit includes a of the material therethrough. The base of each inner unit is of greater Further objects of the invention are to height than the base of each outerunitn er lai) ranged on the base 21 is a super-structure which provides the reducing chamber and consists of a bottom 22, a front wall 23, a rear wall 24, a top wall 25 and a pair of side walls 26, 27. The inner face of the superstructure is such as to provide the reducing chamber of cylindrical cross section. See

Figure 4.

The front wall 23 is formed with a discharge port 28 having the lower portion of the wall thereof iush with the upper `face of the bottom 22 of the reducing chamber. The rear wall" 24 is provided with an intake port 29 which is arranged at a higher level than the discharge port 28. Tap openings for the slag may be provided in the side walls 26, 27, but preferably in wall 26, which opening is indicated at 30 in wall 26 and arranged at the level of the intake port 29. A

The top wall 25 is formed with a iiue 31 for carrying off the gases from the reducing chamber. The flue 31 extends lengthwise of the top wall 25, opens at its front end, as at 32 into the reducing chamber in proximity to the front wall 23, and at its rear end com` municates with a. depending gas conducting pipe 33 which is anchored at its upper end, as at 34 in the upper part of the rear wall 24. rihe pipe 33 is arranged at the rear of the unit, extends down through the foundation 35 which is common to the several units and opens into a gas discharge pipe 36 which is common to the said several gas conducting pipes 33.

The intake ports are positioned relatively to the bottoms of the reducing chambers preferably at a distance whereby the material will have a drop of twelve inches when discharged from a rear reducing chamber into a forward one. i

The discharge port 28 of a rear reducing chamber is arranged in alignment with the intake port 29 of a forward reducing chambei.

interposed between the units 10 and 11, units 11 and 12, units 12 and 13, units 13 and 14, units 14 and 15 and units 15 and 16 are tubular members 37, 38, 39, 40 and 41 respectively. Each tubular member has its inner face registering with a discharge port and an intake port. Each tubular member establishes cemmunication between the reducing chamber of a rear unit with the reducing chamber of a forward unit. Each tubular member provides a material conducting channel 42. Each forward tubular member is arranged below each rear tubular member.

Arranged rearwardly of the reduction upnit 15 is a melting unit 43 providing a preliminary melting chamber 44 for the material to be acted upon. he chamber 44 is of cylindrical contour in sectional plan. The unit 43 includes base of greater height than the base 21 of unit 15. The bottom 46 of chamber 44 is arranged above the bottom 22 of chamber 21. A discharge port 47 is provided for a chamber 44 and which is positioned in alignment with the intake port 29 of chamber 21. Arranged between the units 15 and 43 is a tubular member 48 which registers with the intake port 29 of chamber 21 and discharge port 47 of chamber 44. The member 48 establishes communication between chambers 21 and 44 and provides a passage 49 for the material.

The gas conducting pipe 33 for chamber 21, is formed at its top with an upstanding, angle-shaped branch 50, which opens into the upper portion of the chamber 44, as at 51. The bottoms of-chambers 16 to 21 inclusive and chamber 14 incline downwardly from rear to front and the tubular members incline in a like direction, and which facilitates the travel of the material being treated from the melting chamber to the inner reducing chamber and from one reducing chamber at the rear to a reducing chamber at the front.

Associated with each of the reducing chambers 16 to 21 is a series of heating elements to provide the reducing temperatures. Such temperature may be uniform in each chamber or otherwise, that is to say, each reducing chamber heated separate ata uniform heat or at diiferent heats if desired.

The heating elements are in the form of l electrodes, which may be arranged as shown in Figures 3 and 4 or in the manner as illustrated in Figures 5 and 6. The melting chamber has associated therewith a series of electrodes and which are arranged in the formation as shown.

1n Figure 2 the electrodes are indicated at 53, Figures 3 and 4 at 54 and in Figures 5 and 6 at 55.

A supporting structure 101 is arranf adjacent the unit 42 and is of greater h i than the height of such unit. Mounted .in the structure 101 is an ore hopper 102 and a catalyst hopper 103. Leading from the hopper 102 and discharging into the chamber 44 is an ore chute104. Leading from a source of supply, not shown, is an upstanding conveyor 105 for discharging the material to be treated in the hopper 102.

Positioned within the support 101 is a switch board 106 having attached thereto circuit connections 107 which lead from a source of electrical energy, not shown. Electrically connected with switch board 106 is a transformer 108 from which extends circuit connections .93 for the electrodes.

The apparatus is provided with means for supplying an alloy to a reducing chamber and by way of example such means is illustrated in connection with unit 11. The

means consists of an alloy hopper 109, having a discharge chute 110 which opens at 111 into the reducing chamber provided by unit 11.

The material tobe treated is iirst'supplied said chambers each of said units provided to the unit 43 and initially melted, after with a gas outlet flue and a discharge outlet which it is successively treated in units 15, for slag, and a gas discharge means common 14, 13, 12, 11 and 10. As the material being to the said gas outlet ilues.

treated is travelling through the units 10 3. In an apparatus for the purpose set 7 to 15 both inclusive, the major portion of' forth, a plurality of spaced reduction units the slag will pass out of the ta holes 30, for the continuous travel therethrou h of the but the remaining portion will fa l with the material being treated, each of said units material when supplied from an inner to an 'oviding a reducing chamber, means for 10 outer unit. The material being treated when `scharg1n the material at the bottom of a supplied toa forward unit has afall or drop rear chamer and for su pl ing it into a of preferably twelve inches which assists in forward chamber above the ttom of the throwing off the gases and freeing any matelatter, electrical heating means extending rial that might be reduced that is contained into each of said chambers, each of said units 16 in the slag passing from a rear unit to a forprovided with a as outlet flue and a disward `unit, as when the material drops it charge outlet for ag, the bottom of each of opens up the slag and allows the gases to said reducing chambers inclinin downwardescape and the separation of any reduced ly from rear to front, and means or dischargmaterial from the slag which is carried by ing the material from one unit and supply- 20 the latter. ing it into another unit inclining downward- 85 The material when assing from a rear ly from front to rear. unit to a forward unit ischarges at the bot- In testimony whereof, I affix my signature tom of a rear unit and is supplied into the hereto. forward un'it a substantial distance above ROBERT MCKNIGHT.

p z5 the bottom of the latter, or in other words, the metal is tapped from the bottom of the rear reducing chamber and supplied into a forward reducin chamber above the bottom of the latter. 'he travel of the material 8o from the unit 43 to the unit 10 is by gravity, and the travel thereof is greatly facllitated, due to the inclination of the bottoms of the chambers downwardly from rear to front and such inclined arran ement is also had with respect to the tubular communicating 100 members which are interposed between the units.

The heat employed with res lto the reducing chambers can be as esired, as the 40 heats may be uniform for the several chambers or at different temperatures. Any suitable source o'f heat may be used, electrical preferred. j

What I claim is:

u 1. In an apparatus for the urpose set forth a plurallty of spaced reduction units for the continuous travel therethrough of the material being treated, each of said units providing a reducing chamber, means for discharging the material at the bottom of a rear chamber and for su plying it into a forward chamber above the bottom of the latter, electrical heating means extending into each of said chambers, and each vof said units pro- 56 vided with a gas outlet flue and a discharge 1-20 outlet for slag.

2. In an apparatus for the purpose set forth a plurality of 'spaced reduction units for the continuous travel therethrough of the 5 material being treated, eac'h'of saidnnits pro- 125 viding a reducing chamber, means for discharging the material at the bottom of a rear chamber and for supplying it into a forward y chamber above the bottom of the latter, elec- "s trical heating means extending into each of no 

